Study on Reverse Flotation of Low Grade Phosphate Ore with High Magnesium in Hubei Province

A sedimentary phosphate ore in Hubei contains a low grade P₂O₅ of 21.08% and high magnesium, with collophanite, fluorapatite and dolomite as its main compositions. In order to utilize the low grade phosphate ore, the reverse flotation experimental study was carried out. the proper agent regime and the closed circuit process flowsheet was investigated. The results showed that the phosphor concentrate with P₂O₅ grade of 31.12% and recovery of 88.79% was obtained using MG as collector and phospsoric acid as depressant via the closed-circuit flowsheet of “one roughing-two cleaning, handling of the middlings together”.